The present invention relates to a dual-function medical instrument that combines the general functions of a needle holder and scissors. The present invention also relates to a dual-function instrument that does not present a cutting surface during the normal process of passing a surgical needle through tissue, but does allow the operator to selectively manipulate the instrument so as to be able to sever a surgical suture. The present invention also related to an instrument allowing a surgeon to place and trim surgical sutures without having to change instruments.
Since its inception, surgery has always involved the precise placement of sutures. The act of suturing is fundamental to the successful connection of one piece of tissue to another piece of tissue. Common example include such procedures as the closing of major incisions, repair of skin lacerations, or re-anastamosing blood vessels or segments of intestines.
In a typical example, a suture is mechanically connected to a surgical needle, which is firmly held in gripping instruments resembling elongated pliers, generally called “needle holders,” “needle drivers,” or “forceps,” and all of these terms can be considered to be functionally equivalent. The surgical needle is passed through the two pieces of tissue with the aid of the needle holder and the suture follows the path of the surgical needle. After the suture has been passed through the two pieces of tissue that the surgeon wishes to connect, the suture must be tied into a knot and the ends must be trimmed. For decades, surgical scissors have been used to trim or cut sutures after tying, because scissors can trim or cut without placing any tension on the suture knot placed in the tissues to be joined. This lack of tension in the trimming process is of paramount importance because the tissues to be joined by the surgical procedure are often extremely delicate, especially in applications such as blood vessel surgery, and any tension on the surgical knot might cause the suture to tear through the delicate tissues.
In a typical surgical procedure, many sutures must be placed. For instance, in trauma surgery, sometimes hundreds of sutures must be placed. The operator must either change instruments after every suture is placed, replacing the needle holder with a scissors, or use an assistant to operate the scissors when placing multiple interrupted sutures. Even in the best of cases, this can be a laborious process, but it can easily be appreciated how cumbersome and laborious such a procedure must be in the case of major surgery. Additionally, because of the frequently unavailability of trained personnel and the costs inherent in using skilled assistants, the surgeon is frequently required to work alone without assistance to repair wounds. This latter situation is particularly common in the emergency rooms and doctor's offices and clinics today, as well as in the practice of veterinary medicine, which sometimes may take place in open fields, particularly in the case of large farm animals.
In these situations, the operator is required to change instruments often. In other words, the surgeon must change from scissors to a needle holder after each and every suture is placed. In many cases, each suture must be cut twice. The first cut is necessary to remove the needle from the suture when the suture has been joined mechanically to the needle, and a second time to cut the suture after it has been tied. This very act of changing one instrument for another is cumbersome, time consuming and costly as one or the other instrument can slide off the sterile operative field, requiring the use of additional sterile instruments with their attendant cost. Obviously, in some circumstances, additional sterile instruments may not be available readily, particularly in veterinary practice or in much of the developing world.
A variety of instruments and devices have been proposed and patented to provide the dual function of needle holder and scissors in a single instrument. The overall desirability of such a dual device instrument was cogently expressed by Gmeiner as early as 1940s, and his description of the problems inherent in using two instruments during surgery in the patent issued to him is still relevant today (U.S. Pat. No. 2,315,326).
The present invention is a surgical instrument combining the separate functions of two distinct instruments, one, a needle holder, facilitating the precise placement of sutures, and the second, a scissors, safely cuts suture material without putting any tension on the tissue sutured. This dual function instrument can reliably accomplish both functions without the necessity of the operator repetitively changing instruments from needle holder to scissors throughout the course of surgery, while minimizing the potential to unintentionally cut tissue, or the necessity to use a separate scissors instrument. In other words, the combination needle holder and suture scissors herein described permits the operator to both precisely place the needle and attached suture in tissue, tie a surgical knot with an instrument tie and then cut the suture without putting any tension on the sutured tissue, all without the necessity of changing instruments or using a separate scissors to cut the suture.
However, unlike conventional instruments, such as described in Gmeiner, the present invention does not present a cutting surface in normal usage, particularly when the needle holder is grasping a surgical instrument, such as a surgical needle. The drawback of other dual function instruments, such as Gmeiner, is that an exposed cutting surface is exposed any time the jaws of the instrument are not completely closed. Obviously, a grasping type Instrument cannot remain in fully closed configuration and fulfill its intended purpose. However, when such instruments are opened, the presence of an exposed cutting edge becomes extremely problematic. Given the delicacy of many anatomical structures, any sharp edges are extremely dangerous in a surgical instrument. Even if the edges are not moved towards one another in a cutting motion, many types of tissue, particularly blood vessels, can be damaged by any contact with a sharp edge. And once damaged, some tissues, such as blood vessels, cannot be repaired easily, if at all, and this may cause fatal consequences. Therefore, preventing such inadvertent damage is of paramount concern in surgery. The present invention overcomes the drawbacks of previous designs in that it combines the dual functions of needle holders and scissors, but does not present a sharp edge until the jaws are spread far apart.
All the patents and publications mentioned above and throughout are incorporated in their entirety by reference herein.